JP2563802B2 - Catalyst for olefin polymerization - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention makes it possible to obtain a highly stereoregular polymer which acts highly and has a well-shaped structure when subjected to the polymerization of olefins. It relates to a high performance catalyst. More specifically, the present invention provides a catalyst for olefin polymerization which comprises a special solid catalyst component (I), a specific silicon compound (II) and an organoaluminum compound (III) as described in detail later. Is.

[Prior art and its problems]

Recently, instead of the conventionally known titanium trichloride catalyst component as a solid catalyst component in olefin and other olefin polymerization catalysts, a new type of catalyst component, titanium, which is an active component, is supported on magnesium chloride together with an electron donor. Many things have been developed and proposed.

The earliest of these was developed by co-milling a complex of an organic monocarboxylic acid ester as an electron donor and titanium tetrachloride with magnesium chloride, or an organic monocarboxylic acid as an electron donor. There is a product obtained by treating a co-ground product of an acid ester and magnesium chloride with titanium tetrachloride.

However, when these are used in combination with an organoaluminum compound to industrially polymerize olefins, particularly stereoregular polymerization of propylene, 1-butene, etc., an organic monocarboxylic acid is used as an electron donor during the polymerization reaction. Since it is essential to use an ester, and in this case it is necessary to use an extremely large amount of organic monocarboxylic acid ester, there is a problem that a peculiar ester odor is imparted to the produced polymer.

Further, in these catalysts, although the activity at the initial stage of polymerization is high, deactivation with time is large and becomes a problem in the process operation, and when the polymerization time such as block copolymerization is made longer, it is practically not used. It was impossible.

In order to improve this point, Japanese Patent Application Laid-Open No. 54-94590 discloses a method of preparing a catalyst component using magnesium dihalide as a starting material, and combining an organoaluminum compound, an organic carboxylic acid ester and a compound having a MOR group. Thus, a method for use in the polymerization of olefins is disclosed. However, as is clear from the description of the publication, in this case, it is necessary to use an organic carboxylic acid ester both at the time of catalyst preparation and at the time of polymerization. Generally, the organic carboxylic acid ester contained in the catalyst is treated in an amount such that the odor problem of the polymer produced can be ignored by treatment with a titanium halide or washing with an organic solvent. However, the organic carboxylic acid ester used during the polymerization is extremely large amount as compared with the amount contained in the catalyst as described above, and when the polymerization is carried out in a liquid or gaseous monomer, almost all of it is At present, it is contained in the produced polymer, so that it can be said that the problem of the odor of the produced polymer cannot be solved as long as the organic carboxylic acid ester is used during the polymerization. Further, as can be seen from the examples, the method disclosed in the above publication requires extremely complicated operations and the obtained catalyst is practically sufficient in terms of performance and sustainability of activity. That is not the case.

[Disclosure of Invention]

The present inventors have conducted diligent research in order to solve the various problems in the prior art as described above, and the present invention provides a high-performance catalyst capable of obtaining a polymer having a high degree of stereoregularity. Was successful.

That is, the present invention provides a catalyst for olefin polymerization, which comprises a solid catalyst component of (I) below, a silicon compound of (II) below, and an organoaluminum compound of (III) below.

(I) Magnesium halide (a), tetraalkoxy titanium (b) and diester of phthalic acid (c) in an amount of 2 parts by weight or less relative to 1 part by weight of the magnesium halide (a), -30 ° C to 50 ° C. A homogeneous solution was prepared using an aliphatic hydrocarbon (d) which was liquid at 0 ° C and an aliphatic alcohol (e) which was liquid at -30 ° C to 50 ° C, after which the solution was kept below 0 ° C. To titanium tetrachloride (f) without causing precipitation, and then the temperature of the resulting solution is raised with stirring to precipitate a solid substance, and further with stirring, at a temperature of 80 ° C. or higher, a diester of phthalic acid is produced. A solid product obtained by adding (g) ((c) and (g) may be the same or different) is separated, and an aromatic carbonized liquid which is liquid at room temperature is separated therefrom. Hydrogen or aromatic halogenation Four solid catalyst component obtained Te cowpea in contacting titanium chloride in the presence of hydrogen (H); (II) general formula _{SiR m (OR ') 4-} m ( wherein R represents an alkyl group, a cycloalkyl group , A vinyl group or an aryl group, and R ′ is an alkyl group. When R is an alkyl group, the alkyl group may be the same as R ′. M is 0 ≦ m <4.) The present invention provides a catalyst for olefin polymerization, which comprises a silicon compound represented by the formula (3) and (III) an organoaluminum compound.

The olefin polymerization catalyst of the present invention will be described in more detail below.

First, the solid catalyst component (I) will be described.
The magnesium halide of the above (a) (hereinafter simply referred to as (a)
It is called substance. Examples of) include magnesium chloride, magnesium bromide, magnesium iodide and the like, and among them, magnesium chloride is preferable.

As the tetraalkoxytitanium (b) substance (hereinafter, simply referred to as (b) substance), the alkoxy group having an alkoxy group having 1 to 10 carbon atoms is used, and particularly the one having 3 or 4 carbon atoms is used. It is preferably used.

The phthalic acid diester of (c) above (hereinafter simply referred to as (c)
It is called substance. Examples of) include dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, diamyl phthalate, diisoamyl phthalate, ethyl butyl phthalate, ethyl isobutyl phthalate,
Ethyl isobropyr phthalate etc. can be mentioned as an example.

The amount of (b) and (c) substances used is (a) substance 1
The amount is 2 parts by weight or less based on parts by weight, and for example, it is usually used in the range of 0.01 to 1 g per 1 g of the substance (a).

The aliphatic hydrocarbon (d) (hereinafter simply referred to as the substance (d)) and the aliphatic alcohol (e) (hereinafter simply referred to as the substance (e)) are both liquid at -30 ° C to 50 ° C. Is.

Preferred examples of the substance (d) include aliphatic hydrocarbons having 5 to 12 carbon atoms such as pentane, hexane, heptane,
Octane, nonane, decane, dodecane and the like can be mentioned. Preferred examples of the substance (e) include 2 to 10 carbon atoms.
The aliphatic alcohols such as ethanol, propanol, butanol, pentanol, and hexanol are listed.

The substance (d) and the substance (e) are used in appropriate amounts within a range capable of preparing a homogeneous solution.

Thus, (a) substance, (b) substance, (c) substance,
A homogeneous solution is prepared from the substance (d) and the substance (e), and the resulting solution is added dropwise to titanium tetrachloride (f) kept at 0 ° C. or lower without causing precipitation. In this case, the titanium tetrachloride (f) is used in a proportion of 1 ml or more, preferably 5 ml or more, based on 1 g of the substance (a). After completion of the dropping, the temperature is raised with stirring to precipitate a solid substance, and the diester of phthalic acid (g) is added at 80 ° C. or higher with stirring.

At this time, in order to obtain particles having a good particle shape, it is preferable that the temperature is raised at a rate of 0.5 ° C./min or less.

The (g) phthalic acid diester (hereinafter simply referred to as “(g) substance”) can be appropriately selected from those exemplified as the (c) substance, and it may be the same as or different from the (c) substance. either will do.

The substance (g) is used in an amount of 0.1 ml or more, preferably 0.2 ml or more, per 1 g of the substance (a). (G) After the addition of the substance, the temperature is further maintained at a temperature of 80 ° C. or more for 10 minutes or more, preferably 30 minutes or more.

 The resulting solid product is then separated.

Separation of this solid product is usually carried out by the means used to separate solid substances from liquids, such as decantation or filtration.

Next, the solid product is added to an aromatic hydrocarbon or aromatic halogenated hydrocarbon (H) which is liquid at room temperature (hereinafter simply referred to as (H)
It is called substance. The solid catalyst component (I) is obtained by contacting titanium tetrachloride in the presence of the above (1).

The contact temperature at this time is usually 0 ° C. or higher and 130 ° C. or lower. The contact time is 10 minutes or longer, preferably 30 minutes or longer. Further, the amount of titanium tetrachloride used is 1 ml or more, preferably 5 ml or more based on 1 g of the solid product,
The amount of (H) substance is 0.1 ml to 20 m for 1 ml of titanium tetrachloride.
l, preferably 0.2 ml to 10 ml. In addition, as the (H) substance used at that time, toluene, xylene, o-cyclolbenzene and the like are preferable.

The obtained solid catalyst component (I) may be washed with an organic solvent such as n-heptane or toluene, if necessary, and may be repeatedly treated with titanium tetrachloride or titanium tetrachloride in the presence of the substance (H). You may contact.

All of these aspects are included in one aspect in the practice of the present invention.

The series of operations for preparing the solid catalyst component (I) in the present invention is preferably performed in the absence of oxygen and water.

The solid catalyst component (I) prepared as described above is combined with the silicon compound (II) and the organoaluminum compound (III) to form the catalyst for olefin polymerization according to the present invention. However, examples of the silicon compound (II) include alkoxysilane, phenylalkoxysilane, alkylalkoxysilane, cycloalkylalkoxysilane, and cycloalkylalkylalkoxysilane. Specifically, tetramethoxysilane, tetraethoxysilane, Phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxy Examples thereof include silane, ethyltriethoxysilane, ethyltriisopropoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, divinyldiethoxysilane and divinyldimethoxysilane.

Examples of the (III) organoaluminum compound include trialkylaluminums, dialkylaluminum halides, alkylaluminum dihalides, alkylaluminum sesquihalides, and mixtures thereof. Among them, trialkylaluminums are preferable, and Triethyl aluminum and triisobutyl aluminum are particularly preferred.

The organoaluminum compound (III) is used in an amount of 1 to 1000 mol per g atom of titanium in the solid catalyst component, and the silicon compound is used in a molar ratio to the organoaluminum compound of 1 or less, preferably 0.005 to 1.0. To be

The polymerization reaction using the catalyst for polymerization according to the present invention can be carried out in the presence or absence of an organic solvent, and the olefin monomer used can be used in either gas or liquid state. it can. Polymerization temperature is 20
0 ℃ or less, preferably 100 ℃ or less, the polymerization pressure is 100kg /
cm ² · G or less, preferably 50 kg / cm ² · G or less.

The olefins homopolymerized or copolymerized by using the olefin polymerization catalyst according to the present invention are ethylene, propylene, 1-butene and the like.

〔The invention's effect〕

The catalyst for olefin polymerization according to the present invention, when used for the polymerization of olefins, exhibits an unexpectedly high activity, so that the amount of catalyst residue present in the produced polymer is extremely high. The effect of chlorine can be reduced to such an extent that the product can be kept at a low level and that the residual chlorine is extremely small, so that no deashing step is required for the product.

Since chlorine remaining in the produced polymer causes corrosion of equipment used in steps such as granulation and molding, it also causes deterioration of the produced polymer itself, yellowing, etc. Obtaining is of great benefit to the art.

Further, according to the catalyst of the present invention, by not adding the organic carboxylic acid ester at the time of polymerization, it is possible to solve a big problem that an ester odor adheres to the produced polymer.

Furthermore, conventionally, there was a common drawback in so-called highly active supported catalysts, in which the activity per unit time of the catalyst was significantly reduced with the progress of polymerization, but in the catalyst according to the present invention, Since the decrease in activity with the passage of time is extremely small compared to conventionally known catalysts, it is also useful when prolonging the polymerization time such as copolymerization, and when a higher polymerization pressure is adopted. Because of the large increase in the activity in, it can be widely used in bulk polymerization and gas phase polymerization, which have recently received attention.

Moreover, according to the catalyst of the present invention, a polymer having a regular shape and a high degree of stereoregularity can be obtained.

In addition, in the structure of industrial olefin polymers, coexistence of hydrogen at the time of polymerization is generally considered from the viewpoint of MI control, etc., but conventional magnesium chloride is used as a carrier and organic carboxylic acid ester is used. The catalyst had a drawback that its activity and stereoregularity were significantly reduced in the presence of hydrogen. However, when olefin polymerization is carried out in the coexistence of hydrogen using the catalyst of the present invention,
The activity and stereoregularity are not reduced even when the MI of the produced polymer is extremely high. Such an effect has been strongly desired by those skilled in the art. In addition, in industrial production of polyolefin, the bulk specific gravity of the produced polymer becomes a very large problem in terms of the capacity of the polymerization apparatus, the capacity of the post-treatment step, and the like, but the catalyst according to the present invention also has this problem. And has extremely excellent characteristics.

Further, the polymer produced by using the catalyst according to the present invention has a narrow particle size distribution and is close to spherical.

Further, by using tetraalkoxy titanium and diester of phthalic acid in combination when preparing a uniform solution, it was possible to further increase the particle size of the obtained polymer.

As a result, no undesired fine powdery polymer is produced in the polyolefin manufacturing process, and it is suitable for gas phase polymerization, which has recently attracted attention. Various effects can be exerted, such as simplicity and excellent granule shape, so that the granulation step can be omitted.

〔Example〕

Hereinafter, the present invention will be described more specifically with reference to Examples.

Example 1 (1) Preparation of solid catalyst component Magnesium chloride 4.8 g, tetrabutoxy titanium 2.0 m
l, dibutyl phthalate 1.0 ml, decane 25 ml and 2-ethylhexyl alcohol 25 ml were placed in a 200 ml round bottom flask sufficiently replaced with nitrogen gas, heated to 130 ° C to prepare a homogeneous solution, and then equipped with a stirrer. Capacity 500ml
In a round-bottomed flask at -20 ° C in 200 ml of TiCl ₄ so that precipitation does not occur, and while stirring, the temperature is raised at a rate of 0.2 ° C / min to precipitate a solid product, and dibutyl acetate is added at 110 ° C. 2.0 ml of phthalate was added and stirring was continued at the same temperature for 2 hours. Then, the supernatant liquid is removed, after which the resulting solid product was washed 3 times at room temperature with toluene 200 ml, was added a freshly toluene 50ml and TiCl ₄ 50ml 115
The reaction was performed at 0 ° C for 2 hours. At the end of the reaction, the product is
-Washing with 200 ml heptane 10 times gave a solid catalyst component.

At this time, the titanium content in the solid catalyst component was measured and found to be 2.01% by weight.

(2) Polymerization of propylene Using an autoclave with an internal volume of 2.0 equipped with a stirrer, this was completely replaced with nitrogen gas, and then 200 mg of triethylaluminum, 45 mg of diphenyldimethoxysilane and 5.0 mg of the solid catalyst component were charged. After that, hydrogen gas 1.8
And liquefied propylene 1.4, and a polymerization reaction was carried out at 70 ° C. for 1 hour. After the completion of the polymerization reaction, the produced polymer is
It is dried under reduced pressure at 0 ° C., and the amount of the obtained product is designated as (A). Further, this product was extracted with boiling n-heptane for 6 hours to obtain a polymer insoluble in n-heptane, and the amount of this product is designated as (B).

The polymerization activity (C) per the solid catalyst component used is represented by the following formula.

The yield (D) of all crystalline polymer is represented by the following formula.

Further, the residual chlorine content in the produced polymer is represented by (E), the MI of the produced polymer is represented by (F), and the bulk specific gravity is represented by (G). The obtained results are shown in Table 1.

The obtained polymer had an average particle size of about 390 μm and was transparent.

Example 2 An experiment was conducted in the same manner as in Example 1 except that the polymerization time was 30 minutes. The obtained results are as shown in Table 1.

The obtained polymer had an average particle size of about 300 μm and was transparent.

Example 3 A polymerization reaction was carried out by the following method.

 The experiment was performed in the same manner as in Example 1 except for the above.

700 ml of n-heptane was charged into an autoclave with an internal volume of 2.0, which was completely replaced with nitrogen gas, and 300 ml of triethylaluminum was maintained while maintaining a nitrogen gas atmosphere.
g, diphenyldimethoxysilane 70 mg, then Example 1
15.0 mg of the solid catalyst component prepared by the above method was charged.

Thereafter, 80 ml of hydrogen gas was charged, the temperature was raised to 70 ° C., and propylene gas was introduced while maintaining a pressure of 6 kg / cm ² · G and 1
The polymerization reaction was performed for a time. After the completion of the polymerization reaction, the obtained solid polymer was separated, heated to 80 ° C., and dried under reduced pressure. On the other hand, the amount of the polymer dissolved in the polymerization solvent by condensing the liquid is (H), and the amount of the solid polymer is (I). Further, the obtained solid polymer was extracted with boiling n-heptane for 6 hours,
A polymer insoluble in n-heptane was obtained, and this amount is designated as (J).

The polymerization activity (K) per solid catalyst component is represented by the following formula.

The shrinkage (L) of the crystalline polymer is represented by the following formula, The yield (M) of the whole crystalline polymer is determined by the following equation.

Further, residual chlorine in the produced polymer is represented by (N), MI of the produced polymer is represented by (O), and bulk specific gravity is represented by (P). The results obtained are shown in Table 2.

The average particle size of the obtained polymer was about 190 μm and was transparent.

Example 4 An experiment was performed in the same manner as in Example 3, except that the polymerization time was changed to 2 hours. The results obtained are shown in Table 2.

The obtained polymer had an average particle size of about 270 μm and was transparent.

Example 5 1.0 ml of dibutyl phthalate when preparing a homogeneous solution
An experiment was conducted in the same manner as in Example 1 except that the same amount of dibropyr phthalate was used instead of. The titanium content in the solid catalyst component was 1.90% by weight. An experiment was conducted in the same manner as in Example 1 during the polymerization. The results obtained are as shown in Table 1.

The obtained polymer had an average particle size of about 310 μm and was transparent.

[Brief description of drawings]

FIG. 1 is a schematic drawing for helping understanding of the present invention.

Claims (1)

(57) [Claims] 1. (I) Magnesium halide (a),
2 parts by weight or less of tetraalkoxytitanium (b) and diester of phthalic acid (c), relative to 1 part by weight of the magnesium halide (a), an aliphatic hydrocarbon (liquid) at -30 ° C to 50 ° C ( d) and -30 ° C to 50
A homogeneous solution was prepared using the aliphatic alcohol (e) which was liquid at 0 ° C., and then the solution was added dropwise to titanium tetrachloride (f) kept at 0 ° C. or below without causing precipitation. Then, the temperature of the obtained solution was raised with stirring to precipitate a solid substance, and further with stirring, the diester of phthalic acid (g) ((c) and (g) was the same at 80 ° C or higher. The solid product obtained by the addition of the aromatic hydrocarbon or aromatic halogenated hydrocarbon (H) which is liquid at room temperature is separated.
Solid catalyst component obtained by contacting titanium tetrachloride in the presence of (II) General formula SiR _m (OR ′) _4-m (wherein R is an alkyl group, a cycloalkyl group, a vinyl group or an aryl group). And R'is an alkyl group. When R is an alkyl group, the alkyl group may be the same as R '. M is 0≤m <4.) And (III) A catalyst for olefin polymerization, which comprises an organoaluminum compound.